Thank you for the comment!
I'll take note to maybe make the TVs stand a bit more in the future, along what is interactive and what not.
About where you got stuck I just realized I should have made it a bit obvious given that's one of the biggest stages. You have to go to the other side and try leave through the left side curtain exit, once you do, The Damned will stop you an call you back to the center stage. After the stage interaction, you should be free to exit through the left curtains.
If I got the time I'll go back and add a bit of dialogue so it is a bit more clear what are you supposed to do in the diner level.
On the other hand if The Damned stopped you from leaving and when you approach the center stage (between the two slices of cake and stools) and trying to interact with the stage doesn't do anything then that's a bug I'm going to have to look at because that is bad and should let you do something.